Primary Regulator Valve; Throttle Valve And Downshift Plug; Cut-Back Valve; Secondary Regulator Valve - Jeep 200 Cherokee Service Manual

21 - 230 AW–4 AUTOMATIC TRANSMISSION
DESCRIPTION AND OPERATION (Continued)

PRIMARY REGULATOR VALVE

The primary regulator valve (Fig. 18) modulates
line pressure to the clutches and brakes according to
engine load. The valve is actuated by throttle valve
pressure.
Fig. 18 Primary Regulator Valve
1 – THROTTLE PRESSURE
2 – LINE PRESSURE (FROM MANUAL VALVE "R" RANGE)
3 – LINE PRESSURE (FROM PUMP)
4 – CONVERTER PRESSURE TO CONVERTER CLUTCH RELAY
VALVE
5 – LINE PRESSURE
6 – CONVERTER PRESSURE (TO SECONDARY REGULATOR
VALVE)
7 – DRAIN
8 – DRAIN
During high load operation, the valve increases
line pressure to maintain positive clutch and brake
engagement. At light load, the valve decreases line
pressure just enough to maintain smooth engage-
ment.

THROTTLE VALVE AND DOWNSHIFT PLUG

The throttle valve and downshift plug (Fig. 19)
control throttle pressure to the primary regulator
valve.
The downshift plug and throttle valve are operated
by the throttle valve cam and throttle cable in
response to engine throttle position. Throttle valve
Fig. 19 Throttle Valve And Downshift Plug
1 – LINE PRESSURE CABLE
2 – THROTTLE VALVE CAM
3 – DOWNSHIFT PLUG
4 – THROTTLE VALVE
5 – THROTTLE PRESSURE (TO PRIMARY REGULATOR VALVE)
6 – LINE PRESSURE
7 – CUT-BACK PRESSURE (FROM CUT-BACK VALVE)
pressure is also modulated by the cut–back valve in
second, third and fourth gear ranges.
CUT–BACK VALVE
The cut–back valve (Fig. 20) helps prevent exces-
sive pump pressure buildup in second, third and
fourth gear. The valve is actuated by throttle pres-
sure and by line pressure from the second brake. The
valve also helps regulate line pressure by controlling
the amount of cut–back pressure to the throttle
valve.

SECONDARY REGULATOR VALVE

The secondary regulator valve (Fig. 21) regulates
converter clutch and transmission lubrication pres-
sure. When primary regulator valve pressure exceeds
requirements for clutch engagement or transmission
lubrication, the secondary regulator valve is moved
upward exposing the drain port. Excess pressure
then bleeds off as needed. As pressure drops, spring
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